CombineURLServices

iOS Code Challenge to demonstrate the use of Combine URLSession, Restful API, Core Data, and background processing within a Mobile REDUX Architecture. This solution uses Reducers, Core Data, SwiftUI, and struct View MVVM to manage the data flow and business logic needs for the Use Cases listed below. This architecture will decouple the data flow from the SwiftUI views and will eliminate the dependencies on Singletons and tightly coupled delegate use. SwiftUI uses structs (by value, not by reference) and refreshes to update to a new state. Unlike the UIKit View Controller classes, SwiftUI structs are temporary and the use of delegates and singletons can be risky to implement.

Use Cases and UI/UX Specifications.

1. Single screen with IP address (e.g. 255.255.255.255 format) text input field.
2. Standard Numeric Keyboard. The keyboard shows once the text area is tapped.
3. A single search button initiates a search of the text input field string "content".
4. Restful API: https://ip-api.com/docs/api:json
5. Check, identify, and inform the user interface if the network is lost. Handle API search communication errors.
6. Search results display a dynamic list of returned data from ip-api.com services.
7. Call the ip-api under a refresh rate of 5 minutes (from the first scan). Use the same persisted data on duplicate IP scan requests that have a timestamp under 5 minutes. Require an entry delete and new API refresh RESTful call for any IP address returned after 5 minutes from its' first API call.

Solution Details (WIP)

• Mobile REDUX Architecture using Core Data to decouple the data dependencies and remove the use of Singletons and callback delegates.
• The use of Reducers (REDUX) and Core Data to provide a Data Flow that is decoupled from the struct views of SwiftUI. Allowing SwiftUI to be a temporary in-memory view as intended.
• Use https://github.com/matthewferguson/DataFlowFunnelCD package to manage the Core Data contention issues that exist in older and newer versions of iOS SDKs. Also, centralizes the flow of SQL Create and Updates (CRUD) using Operations.
• Use of Swift Operations and Core Data Fetch Controllers to further decouple the SwiftUI MVVM and Event Driven Data Flow.

Swift Packages installed within the Xcode 15 SPM:

1. Reachability Swift Package Index https://swiftpackageindex.com/ashleymills/Reachability.swift Github: https://github.com/ashleymills/Reachability.swift

2. DataFlowFunnelCD Github: https://github.com/matthewferguson/DataFlowFunnelCD